Complexes of inorganic sodium compounds and chelating amines

ABSTRACT

Chelated inorganic sodium compounds are prepared by mixing an inorganic sodium salt having a lattice energy of not more than about 180 kcal/mole with an aliphatic or cycloaliphatic chelating agent having at least one functionality which is nitrogen and, separated therefrom by two to four carbon atoms, at least one other functionality which is either nitrogen or oxygen. Such compounds have utility as catalysts, as additives, in separations, in making batteries, and in synthetic chemistry.

United States Patent Bunting 1 Sept. 11, 1973 COMPLEXES 0F INORGANICSODIUM [56] References Cited COMPOUNDS AND CHELATING AMlNES UNITEDSTATES PATENTS Inventor: William Bunting, Baton Rouge, 3,258,490 6 1966Bedell 260/583 P La. 3,541,149 ll/l970 Langer 260/563 R [731 Assignees:Arthur W. Langer,Jr.,Watchung;

E550 Research and Engineering Primary Examzr zer Lewis Gotts CompanyLinden, both Assistant Exammer-Rmhard L. Raymond Attorney-Chasan andSmnock and Harold Emhorn 22 Filed: July 27, 1970 [21] pp 58,660 57ABSTRACT Chelated inorganic sodium compounds are prepared by Cl 260/5333 260/239 mixing an inorganic sodium salt having a lattice energy 260/60/2 260/293 of not more than about 180 kcal/mole with an aliphatic 260/6 260/ 260/4293, 260/4295, or cycloaliphatic chelating agent having atleast one functionality which is nitrogen and, separated there- 260/435,260/4331, 2 260/439, from by two to four carbon atoms, at least oneother 260/ 0, 260/ functionality which is either nitrogen or oxygen.Such 260/563 R, 260/531 C compounds have utility as catalysts, asadditives, in sep- Clm C076 C076 C070 37/54 arations, in makingbatteries, and in synthetic chemis- [58] Field Of Search 260/583 R, 583P, tr

6 Claims, No Drawings COMPLEXES OF lNORGANlC SODIUM COMPOUNDS ANDCHELATING AMINES Tl-IE PRIOR ART It is known that it is possible toobtain stable catalytic complexes comprising organolithiums complexedwith bifunctional Lewis bases, particularly with nonaromatic tertiarydiamines (U.S. Pat. No. 3,451,988) for use mainly in polymerization andtelomerization reactions. It is also known that the use of organosodiumand organolithium in the place of the organolithium component in theabove catalytic complex will reduce the chain length resulting fromtelomerization reactions (US. Pat. No. 3,206,519). Further, recentpublications (Dutch Pat. application Nos. 6804412 and 6804487) haveattempted to show that complexes of the above type may be prepared fromorganosodium complexed with a tertiary aliphatic diamine. These lattercomplexes are so unstable as to be unisolatable.

It is also known that polyethers have the ability to solvate sodiumcations. In a number of cases stable polyether chelates of sodium saltscontaining a transition metal complex anion have been isolated (U.S.Pat. No. 3,214,452). There is, however, no mention in the literature ofthe possibility of obtaining stable compounds by reaction of inorganicsodium salts with aliphatic chelating agents having nitrogen as afunctional group.

THE PRESENT INVENTION It has now been unexpectedly discovered thatstable chelated inorganic sodium compounds can be prepared by complexingan inorganic sodium salt with aliphatic or cycloaliphatic chelatingpolyamines and aminoethers. It is well known that one of the significantfactors used in predicting whether a reaction can be accomplished with agiven material is whether the lattice energy of such material is lowenough to be overcome by other reactants so as to form a new compound.Thus, it was highly surprising to find that the inorganic sodium salts,which have significantly higher lattice energies than organosodiums suchas those of the prior art, can nevertheless form stable complexes.

it should be understood that for the purposes of this invention, theterm inorganic sodium means that there is no hydrocarbon radical bondeddirectly to the sodium atom and any hydrocarbon radical present in theanion moiety must be indirectly bonded to the sodium through a thirdatom other than carbon. Thus, sodium compounds such as n-butylsodium andphenylsodium do not meet the criteria and are outside the scope of thisinvention. n the other hand, compounds of the type NaNH NaCN, NaSCN,NaSl'l, Na CO Nal-l- CO NaAlR,Cl NaAll-l(OR) NaOl-l, NaOR, NaNHR, NaBHNaNR NaSR, NaPR and NaOOCR are inorganic sodium compounds within thescope of this invention.

Useful inorganic sodium salts include, but are not limited to, those inwhich the anion is a complex metal anion which may be represented by theformula other than carbon and silicon, Group V-A elements other thannitrogen (i.e., P, As, Sb, Bi), and the transition metals (i.e.,Subgroup B of Groups lV through Vlll (i.e., Fe, Co, Ni, Ti, Zr, V, Cr,Nn). The Periodic Table employed in describing this invention is thatwhich appears on the back cover of Handbook of Chemistry and Physics,(Chemical Rubber (30., 49th Ed.).

Nonlimiting examples of useful anions include the hydridoaluminates, thehydridoborates, the chloroaluminates (tetra-, hepta-, etc.), thealuminum and boron alkyl halides, the aluminum and boron tetraalkyls and-aryls, AuBrf, BFf, PF FeClf, Cr(CO) l, W(CO) Br MnCl VF HgCl B Hf, UFf,AsF ClOf,.SCN 1, Br, N N0 O-t- Bu, NMe Sqb.

Preferably, the inorganic sodium salt is one of the following: NaBr,Nal, NaN NaBH NaB H NaAlH NaNO NaClO NaBF NaSCN, NaNMe NaO-t-Bu, NaS,NaAlEt,, NaBBu,, NaBl-lEt NaAlH Et NaAlH Odi, NaPF NaFeCl NaCr(CO) l.

The chelating agent of the present invention must be aliphatic orcycloaliphatic and contain at least two functional groups, saidfunctional groups being spatially related to one another in such manneras to allow formation of a stable chelate with the sodium atom of theinorganic sodium salt. The functional groups may be either of two types.The first type is selected from the group consisting of a secondaryamine group and a tertiary amine group; the second type is selected fromthe group consisting of a secondary amine group, a tertiary amine group,and an ether group. In other words, the chelating agent must be analiphatic or cycloaliphatic chelating polyamine or aminoether.

The chelating agent may be sparteine, an N,N'-di-(C C alkyl) 'bispidin,tris-2(dimethylaminoethyl)-amine as well as those compounds fallingwithin the scope of the following general formulas:

wherein a is l or.2,b is 0 or 1, and a b 2; c is an integer ofO to10,000, inclusive; d is 0 or 1, depending on the valance of Y; e is aninteger from 0 to 3, inclusive;fis0or l,a' is l or2,b'=0or l anda'+b'= lor 2, depending on the valence of Y; R is the same or different C -Calkyl radical; R is hydrogen or is the same or different C -C alkylradical or C -C aryl or aralkyl radical; Y is anitrogen or oxygen atom;and Z Cis-N,N,N', N '-tetramethyl 1,2- cyclopentanediamine; N,N,N,N'-tetramethyl-l ,2- cyclohexanediamine (cis-, trans-, or mixtures)(TMCHD); N,N,N',N'-tetramethyl-l,Z-ethanediamine (TMED);N,N,N,N'-tetramethyl-l,3-propanediamine (TMPD);N,N,N',N",N"-pentamethyl-diethylenetriamine (PMDT); N,N,N,N-tetramethyl-1,2- propanediamine (TM 1 ,2PD); N,N'-dimethyl-N,N'-

diethyl-l,Z-ethanediamine; N,N,N,N-tetramethyl-lcyclohexyl-l,Z-ethanediamine; N,N,N',N'-tetramethyl- 2,3-butanediamine; N,N,N,N'-tetramethyl-l ,4- butanediamine;N,N,N",N"',N"-hexamethyltriethylene-tetramine (HMTT);tris-(fl-dimethylaminoethyl- )amine(iso-HMTT);octamethylpentaethylenehexamine (OMPH);heptamethyltetraethylenepentamine (HMTP);N-B-dimethylaminoethyl),N,N,N'- trimethylcyclohexane-l,Z-diamine; methyldi-(y-dimethylaminopropyl)amine; poly-(N-ethyl-ethyleneimine);

poly-(N-methyl ethyleneimine); beta- (dimethylamino)ethyl methyl ether;beta- (diethylamino)ethyl ethyl ether; bis-(betadimethylamino)ethylether; beta-(dimethylamino)- ethyl ethyl ether;gamma-(dimethylamino)propyl methyl ether; 1,2-dipiperidylethane; tris-(l ,3,5- dimethylamino) cyclohexane; N,N,N"-trimethyl-1,3,5-hexahydro-s-triazine; etc.

Preferred chelating agents include sparteine, an N,N'-di-(C,-C )alky1bispidin, tris- 2(dimethylaminoethyl) amine and those compounds fallingwithin the scope of Formula I above. Particularly preferred species ofthe chelating polyamines are PMDT, HMTT, iso-HMTT, HMTP, OMPH, poly-(N-methyl ethyleneimine), etc. Particularly preferred species of theaminoethers are bis-(betadimethylamino)ethyl ether,tris-(beta-methoxyethyl) amine, etc.

Not all inorganic sodium compounds form complexes with theabove-described chelating agents. It is, however, possible to relatesuccess in chelating inorganic sodium compounds to the lattice energy ofthe unchelated sodium compounds and to find an approximate cutofflattice energy above which chelation does not occur. This cutoff latticeenergy has been experimentally determined to be about 180 kcal/mole.Since the ability to form chelates is obviously dependent on thechelating agent employed, this cutoff lattice energy is also chelatingagent dependent; i.e., only chelating agents capable of forming the moststable complexes will chelate sodium salts having lattice energies inthe area of 180 kcal/mole.

The chelated sodium compounds decompose upon heating to give theunchelated inorganic sodium compound as a precipitate and free chelatingagent in solu-' tion. Upon cooling, this reaction is reversible. Thetemperature at which the uncomplexed salt precipitates is quite sharp(1-2) and reproducible. Using this information, it was possible todetermine the relative thermal stabilities of the chelated sodiumcompounds. Table l, below, contains decomposition temperatures for avariety of chelated sodium compounds. These temperatures were obtainedby synthesizing the chelated sodium compound in benzene, filtering thereaction to give a clear solution, and heating the solution in an oilbath at the rate of about lC./min. The temperature at which saltprecipitates was taken as the decomposition temperature.

TABLE I CHELATE DECOMPOSITION TEMPERATURES NaBH, Temp., C. PMDT 45HM'I'I 45-46 iso-HMTT 56-58 HMTP 50-51 Nal PMDT -72 HMTT 2 HMTP 50-51OMPH 60-69 NaOtBu PMDT 65 HMTT From this information it can be seen thatthe thermal stabilities of the chelated sodium compounds are chelatingagent dependent; e.g., chelates of iso-HMTT are more stable than thoseof HMTT, which are more stable than those of PMDT, which in turn aremore stable than those of TMED. This same order can be seen for thecutoff lattice energy which, as already stated, is also chelating agentdependent. Table 11, below, lists some inorganic sodium compounds inorder of increasing lattice energy and the results of attempts tochelate these compounds with iso-HMTT, HMTT and PMDT.

TABLE [I COMPLEXATION DEPENDS ON LATTICE ENERGY Complex FonnationLattice HMTT, PMDT [so-HMTT Compound Energy Yes No Yes No NaClO. 159-175x NaSCN 163-178 x Nal 164-166 x NaBH. 168 x x NaN, 169-175 x x NaNO,173-181 x x NaBr 176-178 x x NaCN 177-185 at x NaOAc 182-198 x NaCl185-186 x NaNO, 185-201 x NaH 193-202 x NaOH 211 x Several authors ascompiled in M.F.C. Ladd and W. H. Lee in H. Reiss, ed., Progr. SolidSlate Chem, Vol. I, Pergamon Press, bondon, 1964.

The complex of the inorganic sodium salt may be readily prepared bymixing the selected inorganic sodium salt (having the requisite maximumlattice energy) with the selected chelating agent in the absence ofsolvent. Such mixing may also be accomplished in the presence of inerthydrocarbons, e.g., C,--C alkanes (e.g., pentane, heptane, hexadecane);C,;C aromatics (e.g., benzene, toluene, xylene, dibutylnaphthalene);halogenated aliphatics and aromatics (e.g., chloroform, methylenedichloride, chlorobenzene, dichlorobenzene, hexafluorobenzene);heterocyclic compounds (e.g., pyridine, pyrrole, furan, thiophene,sulfolane, borazole); polar solvents (e.g., ketones, dimethylsulfoxide,acetonitrile, dimethylformamide, liquid ammonia, triethylamine,propylene carbonate, ethers, etc.); or mixtures thereof.

The amount of the diluent is not critical and amounts in the range ofOto 99.9 wt. percent, based on the chelated sodium salt may beconveniently employed. Thus, the chelate may be formed in the absence ofsolvents, in the form of pastes and in solutions.

In those situations where the inorganic sodium salt of choice is notsolubilized by the admixture of the chelating agent and solvent, thechelate may be formed by mixing the inorganic sodium salt (which ispreferably in finely divided form) with the chelating agent of choice instoichiometric amounts, or preferably, with excess chelating agent.

Another method for preparing the chelate involves anion exchange. Inthis method, the chelating agent of choice is mixed with an inorganicsodium salt (in which the anion is not the desired anion) by one of themethods described above. Thereafter, the resultant chelate is subjectedto anion exchange in the presence of a metal salt (or other well knowntechniques such as anion exchange resins) containing the anion ofchoice; alternatively, all components may be mixed simultaneously andboth chelation and metathesis occurs in situ.

Another method for preparing the chelate is analogous to the precedingmethod except that here the anion is one of choice, but the chelatingagent is not one of choice. After preparing the non-preferred chelate byone of the above methods, the non-preferred chelating agent moiety isexchanged for the preferred chelating agent moiety by mixing the chelate(utilizing one of the former methods) with the desired chelating agentand thereafter recovering the desired chelate.

Regardless of the method employed the preparation of the chelate ispreferably carried out under anhydrous conditions, although this is notalways necessary in some applications, such as separations.

The complex may be readily prepared at temperatures from about -l00C. toabout 150C.; preferably 0 to 100C.; the latter temperature range ispreferred because of convenience and also since higher temperaturesfavor dissociation of the less stable complexes. Pressures may rangefrom subatmospheric to 100 psig or more. For convenience sake,atmospheric pressures are preferred.

The molar ratio of inorganic sodium compounds to chelating agent is notcritical and from about 0.1 to about 50, preferably 0.5 to 10, moles ofchelating agent per mole of inorganic sodium are generally employed; thechelating agent may also be employed as a solvent. However, it should beunderstood that the amount of chelating agent employed may influence thestructure of the resultant chelate. In this regard it has been foundthat true chelate formation occurs only with certain specific ratios;that is, if an incorrect ratio (for true compound formation) wereemployed, the product would have predominantly the composition of thenearest true compound and it would consist of a mixture of severalcompounds. Although 1:1 complexes are preferred, it is within the scopeof this invention to prepare and isolate complexes of otherstoichiometries such as 1:2 and 2:1.

Of course, the minimum amount of chelating agent should be thatstoichiometric amount required to produce the desired type of chelate(where more than one type of chelate is possible from a particularinorganic sodium and a particular chelating agent). Where only one typeof chelate can be formed or where one is not concerned with theparticular type of chelate to be formed (assuming that more than onetype is possible), it is desirable to employ amounts of chelating agentin excess of the stoichiometric amount.

One of the uses of the complexes of this invention is the separation andpurification of the chelating agents. Advantage may be taken of thefact, shown previously, that stability of the chelate depends upon thetemperature of the reaction medium; higher temperatures favordissociation of the less stable complexes. Temperature, then, may beadjusted to selectively complex the desired chelating agent. Incombination with, or as an alternative to, temperature control, theseparations may be made by careful selection of an inorganic sodium salton the basis of its lattice energy. Only the chelating agents capable offorming the most stable chelates will complex an inorganic sodium salthaving a lattice energy near the previously stated maximum. Therefore,it is obvious that the more stable chelating agent can be separated fromthe less stable ones. It is also obvious that chelating agents may beseparated, not only from one another but from other compounds orimpurities which do not have the ability to chelate the sodium salts ofthe present invention.

A variation of this separation technique, i.e., using chelating agentsto separate inorganic sodium salts from one another and from other saltsor impurities including other Group l-A and Group ll-A inorganic salts,may also be employed. Thus, for example, a solid mixture of sodiumchloride and sodium iodide may be contacted with a chelating agent suchas PM DT in benzene and a benzene soluble PMDT-Nal complex will formleaving the sodium chloride behind. The pure sodium iodide may berecovered by heating the solution to C., which destabilizes the complexand precipitates sodium iodide. A similar procedure can be followed toseparate a salt such as sodium iodide from another Group ll-A or lI-Asalt or salt mixture such as, for example, potassium iodide.

The pure sodium salt and the chelating agent can each be readilyobtained from the complex by destabilization of the complex, e.g., byheating as discussed above, by addition of aqueous or anhydrous acids orbases (e.g., HCl, H NaOH, diglyme, KOH, etc.), etc. Separation of thechelating agent from the sodium salt is done preferably by heating,since both components are recovered pure by this procedure withoutconsuming additional chemicals.

The purification and/or separation processes described above may, ofcourse, be advantageously utilized with column and counterfiowtechniques, e.g., the inorganic sodium salt (complexed or uncomplexed)may be contacted with a counterflow of a hydrocarbon solution of thechelating agent and the resultant complex may then be subjected todestabilization to recover the desired chelating agent.

Other uses for the novel complexes of the present invention include useas additives, e.g., as oxygen or carbon dioxide scavengers inpurification processes; as catalysts, e.g., in metalation andpolymerization; in making batteries; as reducing agents, and insynthetic chemistry.

This invention may be illustrated, but is not limited to, the followingexamples:

EXAMPLE 1 PMDT NaOtBu To 2.4 g (25 mmoles) of sodium t-butoxide wereadded 25 ml benzene and 5.5 ml (-25 mmoles) PMDT. The solution wasstirred overnight at room temperature and then filtered. The precipitateweighed 0.98 g. The solution was slowly and partially evaporated to givewhite crystals which were filtered off. Elemental analysis showed thatthe crystals were sodium t-butoxide. Sodium t-butoxide itself is notsoluble in benzene. The solubility of sodium t-butoxide in benzene inthis experiment is ascribed to the formation of a benzene solublecomplex between sodium t-butoxide and PMDT. The complex is not stableenough to be isolated under the conditions of this experiment. Calcd.for NaO-t-butyl: C, 50.0; H, 9.4; Na, 24.0. Found: C, 46.98; H, 9.04; N,0.1; Na, 24.69.

EXAMPLE 2 PMDT NaAlH,

To 0.68 g (12.5 mmoles) sodium aluminum hydride were added 25 ml benzeneand 2.8 ml (-12 mmoles) PMDT. After stirring 2 hours, 2.8 ml more PMDTwas added. The solution remained cloudy and was stirred overnight andfiltered. The filtrate was allowed to slowly and partially evaporate togive white crystals of PMDT 0 NaAlH EXAMPLE 3 PMDT o NaBH,

To 0.48 g (12.5 mmoles) sodium borohydride were added 25 ml benzene and2.8 ml (-l2.5 mmoles) PMDT. Upon stirring, the reaction became asolution containing a small amount of finely divided precipitate. Theaddition of 2.8 ml more PMDT gave the visual impression that the amountof finely divided precipitate suspended in solution had decreased. Afterstirring overnight, the reaction was filtered. The filtrate was allowedto slowly and partially evaporate to give white crystals of compositionPMDT 6 NaBH,. Calcd. for PMDT 0 NaBH C, 51.2; H, 12.9; N, 19.0. Found:C, 51.6; H, 13.3; N, 20.1. Despite the twofold excess of PMDT, only thePMDT e NaBH, complex could be isolated, not the (PMDThNaBH complex.

EXAMPLE 4 To 1.38 g (12.5 mmoles) sodium fluoroborate were added 25 mlbenzene and 3.7 ml (-12.5 mmoles) HMTT. The reaction was stirredovernight at room temperature and filtered. The filtrate was allowed toslowly and partially evaporate to give crystals of composition HMTT oNaBF,. Calcd. for HMTT 0 NaBF C, 42.4; H, 8.9; N, 16.5. Found: C, 43.1;H, 9.3; N, 16.4.

EXAMPLE 5 PMDT o NaNMe To 1.4 g (21 mmoles) of sodium dimethylamide(synthesized from dimethyl amine and-benzylsodium) were added 25 mlbenzene and 3 g (17 mmole) PMDT. The reaction was stirred 2 hours andfiltered. The filtrate was allowed to slowly and partially evaporate togive crystals of composition PMDT w NaNMe Calcd. for PMDT NaNMe C, 55.0;H, 12.1; N, 23.3. Found: C, 55.3; H, 12.3; N, 23.0.

EXAMPLE 6 HMTT 0 Nal To 1.5 g 10 mmoles) Nal were added 25 ml benzeneand 2.3 g 10 mmoles) HMTT. The reaction was stirred 2 hours to givecomplete solution. The solution was slowly and partially evaporated togive white crystals of composition HMTT Nal. Calcd. for HMTT 0 Nal: C,37.9; H, 7.9; N, 14.7; 1, 33.4. Found: C, 39.2; H, 8.2; N, 15.0; 1,31.5.

In a similar manner PMDT O Nal was prepared. Calcd. for PMDT Nal: C,33.6; H, 7.1; N, 13.0; 1, 39.5. Found: C, 33.6; H, 7.2; N, 13.1; 1,40.8.

EXAMPLE 7 PMDT Q NaSCN To 0.81 g (10 mmoles) sodium thiocyanate wereadded 25 ml of benzene and 2.2 ml (-10 mmoles) PMDT. The reaction wasstirred overnight and filtered to give solid A. The filtrate was slowlyand partially evaporated to give solid B. Both solids had compositionPMDT 0 NaSCN. Calcd. for PMDT 0 NaSCN: C, 47.2; H, 9.0; N, 22.0. Foundfor solid A: C, 45.8; H, 8.9; N, 21.3. Found for solid B: C, 48.1; H,9.6; N, 28.6.

EXAMPLE 8 PMDT NaClO.

To 0.62 g (5 mmoles) NaClO, were added 25 ml benzene and 1.1 ml PMDT (-5mmoles). The reaction was stirred overnight and filtered to give solidA. The filtrate was slowly and partially evaporated to give whiteneedles (solid B). Solids A and B had composition PMDT o NaClO.,. Calcd.for PMDT 0 NaClO,: C, 36.6; H, 7.8; N, 14.2. Found for solid A: C, 30.4;H, 6.8; N, 13.8. Found for solid B: C, 39.0; H, 8.4; N, 14.0.

EXAMPLE 9 lso-HMTT Q NaNO To 0.34 g (4 mmoles) NaNO in one barrel of adouble-barrel Schlenk tube fitted with a fritted filter were added 7 mlbenzene and 1 ml (-4 mmoles) iso-HMTT. The barrel containing thereaction mixture was put into a cold water bath maintained at 10. Afterstirring 1% hours a white ppt. remained. The reaction was filtered fromone barrel to the other and allowed to stand at room temperatureovernight with no visible change. The filtrate was put on a vacuum lineand the benzene removed. When about 1 ml of solution remained, thefiltrate was heated to about for several minutes. A white ppt. formedwhich readily redissolved upon addition of one-half ml of benzene,indicating that the precipitate was chelated sodium nitrate. An LR. ofthe solution had bands at about 1,360 and 840 cm, typical of inorganicN0 I EXAMPLE 10 PMDT NaBH,

To 0.38 g (10 mmoles) NaBH, were added 25 ml heptane and 2.2 ml (-10mmoles) PMDT. The reaction was stirred 3 hours, and filtered to givesolid A. The filtrate was partially evaporated to give white crystalswhich were filtered off, dried and labeled solid B. Calcd. for PMDT ONaBH C, 51.2; H, 12.9; N, 19.9. Found for solid A: C, 5.06; H, 10.68; N,2.67. Found for solid B: C, 49.74; H, 13.30; N, 19.68.

This experiment shows that the paraffinic hydrocarbons may also besuitable solvents for preparing chelated sodium compounds. a

EXAMPLE ll Separation of Nal and NaCl To 0.5 g Nal and 0.5 g NaClsuspended in 25 ml. of benzene was added 2.2 ml PMDT. The reaction wasstirred overnight and filtered to give solid A. Solid A was washed withbenzene, dried and analyzed. The filtrate was evaporated under vacuum togive solid B which was analyzed. Calcd. for initial mixture: Cl, 30.5;I, 42.5. Found for solid A: I, 5.63; CI, 59.38. Found for solid B: I,42.73; Cl, 0.00. Calcd. for PMDT Nal: I, 39.5.

This experiment shows that sodium iodide and sodium chloride can beseparated by selective chelation.

EXAMPLE l2 Separation of Sodium Iodide and Potassium Iodide To 0.5 gsodium iodide and 0.5 g potassium iodide suspended in 25 ml benzene wasadded 2.2 ml PMDT. The reaction was stirred overnight and filtered togive solid A. Solid A was washed with benzene, dried, and analyzed. Thefiltrate was evaporated under vacuum to give solid B. Calcd. for initialmixture: Na, 7.65; K, 11.7. Found for solid A: Na, 0.22; K, 4.73. Foundfor solid B: Na, 7.01; K, 0.02. This experiment shows that sodium iodideand potassium iodide can be separated by selective chelation.

EXAMPLE l3 Separation of Sodium Perchlorate and Sodium Iodide To 0.75 gsodium iodide (5 mmoles) and 0.60 g sodium perchlorate (5 mmoles)suspended in 25 ml benzene was added 0.87 g (5 mmoles) PMDT. Thereaction was stirred 2 hours and filtered to give solid A (0.88 g).Solid A was washed with benzene, dried, and

analyzed. The filtrate was evaporated under vacuum to give solid B.Calcd. for initial mixture: Cl, 12.9 I, 47.0. %I/%Cl: 3.64. Found forsolid A2 Cl, 6.52; I, 57.02. %I/%C1: 8.8. Found for solid B: Cl, 8.73;I, 10.53. %I/%Cl: 1.2.

This experiment shows that two sodium compounds forming relativelystable amine chelates can be partially separated in one stage by thedifference in stability of their complexes. Therefore, the use ofadditional chelating stages should allow complete separation of quitesimilar sodium salts.

EXAMPLE 14 Separation of Sodium Borohydride and Sodium Iodide To 0.12 g(3 mmoles) sodium borohydride and 0.45 g sodium iodide (3 mmoles) wereadded 1.3 ml (6 mmoles) PMDT and 7 ml benzene. The solution was heatedto 60 and filtered. Infrared showed a marked decrease in the B-I-I bandin the filtrate compared with the original solution. The filtrate wasevaporated to give 1.08 g solid (theoretical yield of PMDT 0 Nal is 0.97g).

This experiment is qualitative rather than quantitative, but still showsthat sodium borohydride and sodium iodide can be partially separated bytaking advantage of the difference in their thermal stabilities.

EXAMPLE 15 OMPH I Nal To 1.5 g (10 mmoles) of sodium iod de were added25 ml benzene and 4.3 ml (10 mmoles) OMPH. The reaction was stirredovernight and filtered. The filtrate was slowly and partially evaporatedto give crystals of OMPH 0 Nal. Calcd. for OMPH 0 Nal: C, 43.3; H, 8.91;N, 17.0. Found: C, 44.8; H, 8.91; N, 17.93.

EXAMPLE 16 To 2.3 g l0 mmoles) ofa mixture of iso-HMTT and HMTT(21.8:78.2) in 15 ml of n-pentane was added 0.325 g (2.2 mmole) ofsodium iodide with stirring. A fluffy precipitate formed almostimmediately replacing the gramular sodium iodide. The reaction wasstirred overnight and filtered. GC analysis showed the composition ofthe filtrate to be (iso-I-IMTT:I-IMTT) 04:99.6.

This experiment shows that iso-HMTT can be selectively and simplyremoved from a mixture of iso-I-IMTT and I-IMTT by selectivecomplexation w ith sodium salts. The alternative method of separationinvolves a lengthy and careful fractional distillation.

EXAMPLE I? A mixture of 1.45 g N,N', N"-trimethyldiethylenetriamine(TriMDT) (IO-mmoles) and 1.52 g powdered sodium iodide (10 mmoles) in 50ml benzene was stirred 5 days at 25-30C. under nitrogen. After filteringoff 1.96 g of white solid, the filtrate was evaporated yielding a whitecrystalline residue which was washed with heptane, filtered and vacuumdried. The TriMDT Nal chelate weighed 0.34 g. This example shows thatchelating polyamines containing secondary amine functionality may beused to prepare chelates of sodium salts.

While the above examples adequately illustrate the invention, it shouldbe understood that the present invention in its broadest aspects is notnecessarily limited to the specific materials, conditions and proceduresshown therein. The present invention is limited only by the claims whichfollow.

What is claimed is:

1. A complex of:

a. an inorganic sodium salt having a lattice energy of not more thanabout kcal per mole and b. an aliphatic or cycloaliphatic tertiarychelating hydrocarbyl polyamine.

2. A complex of:

a. an inorganic sodium salt having a lattice energy of not more thanabout 180 kcal per mole and b. an aliphatic or cycloaliphatic chelatingagent selected from the group consisting oftris-2(dimethylaminoethyl)-amine and those compounds falling within thescope of the following general formula whereinais 1 or 2,bis'0orl,anda+b=2;cisan integer of 0 to 10,000, inclusive; d is 0 or 1,depending on the valence of Y; a is 1 or 2, b' 0 or 1 and a b' l or 2,depending on the valence of Y; R is the same or different C -C alkylradicals; Y is a nitrogen or oxygen atom; and Z is a nonreactive radicalselected from the group consisting of l) C C cycloaliphatic radicalswherein said radicals are attached to the nitrogen and Y atoms inFormula I at 1,2- or Lil-positions on the cycloaliphatic rings; and (2)one to four methylenic radicals wherein each methylenic radical containszero to two monovalent hydrocarbon radicals of one to six carbon atoms.

3; The complex of claim 2 wherein the chelating agent is selected fromthe group consisting of tris- 2(dimethylaminoethyl)-amine and compoundshaving the following formula:

(H)b Ldlld Jo (IiDb' oxygen atom; and Z is a nonreactive radicalselected from the group consisting of l) C C cycloaliphatic radicalswherein said radicals are attached to the N and Y atoms at 12- or1,3-positions on the cycloaliphatic rings, and (2) one to fourmethylenic radicals wherein each methylenic radical contains zero to twomonovalent hydrocarbon radicals of one to six carbon atoms.

4. The complex of claim 1 wherein the chelating agent is selected fromthe group consisting of N,N,N, N",N"-pentamethyldiethylenetriamine,N,N,N',N",N- "',N"'-hexamethyltriethylenetetramine, tris-(B-dimethylaminoethyl)amine, heptamethyltetraethylenepentamine,octamethylpentaethylenehexamine, and poly-(N-methylethyleneimine).

5. A complex according to claim 1 wherein said chelating polyamine istris-2(dimethylaminoethyl)-amine.

6. A complex according to claim 1 wherein said sodium salt is sodiumdimethyl amide and said tertiary chelating hydrocarbyl polyamine isN,N,N,N",N- pentamethyl-diethylene-triamine.

V UNITED STATES PATENT OFFICE 1 CERTIFICATE OF CORRECTION Patent No,3,75 ,5 5 Dated September 11, 973

Inventor) William M. Bunting and Arthur W. La ger, Jr,

It is certified that error appears in the above-identified patent thatsaid Letters Patent are hereby corrected as shown below:

Cover page, under "United States Patent [19]", "Bunting" should readBunting et al "[75] Inventor: William M. Bunting, Baton Rouge, La.should read [75] Inventors: William M. Bunting, Baton Rouge, La. 5

' v Arthur W. Langer, Jr., Watchung; both of N.J. 1 [73] Assignees:Delete "Arthur W. Langer, Jr., Watchungg, and change "both of 'N'.J." toread N.J.

Signed and sealed this lst day of January lQYL (SEAL) Attest: v

EDWARD M.FLETCHER,JR. RENE: D. TEGTMEYER Attesting Officer ActingCommissioner of Patents FORM PO-IOSO (IO-59) USCOMWDC 603764369 w u.s4eovznnuzm' PRINTING OFFICE nu o-su-as4.,

Patent No, 3, 75 5 5 Dated September 973 Inventor(s) William M. Buntingand Arthur W. Langer,

It is certified that error appears in the above-identified patent thatsaid Letters Patent are hereby corrected as shown below:

Cover page, under "United States Patent [19], "Bunting" should readBunting et al "[75] Inventor: William M. Bunting, Baton Rouge, La.should read [75] Inventors: William M. Bunting, Baton Rouge, La. 3

, Arthur W. Langer, Jr., Watchung;

both of N.J. [73] Assignees; Delete "Arthur W. Langer, I Jr., Watchung;and change "both of N.J." to read N.J.

Signed and sealed this lst day of January 197L (SEAL) Attest:

EDWARD M.FLETCHER,JR. RENE D. 'lE(:TMIEDZER Attesting; Officer ActingCommissioner of Patents

2. A complex of: a. an inorganic sodium salt having a lattice energy ofnot more than about 180 kcal per mole and b. an aliphatic orcycloaliphatic chelating agent selected from the group consisting oftris-2(dimethylaminoethyl)-amine and those compounds falling within thescope of the following general formula
 3. The complex of claim 2 whereinthe chelating agent is selected from the group consisting oftris-2(dimethylaminoethyl)-amine and compounds having the followingformula:
 4. The complex of claim 1 wherein the chelating agent isselected from the group consisting of N,N,N'',N'''',N''''-pentamethyldiethylenetriamine,N,N,N'',N'''',N'''''',N''''''-hexamethyltriethylenetetramine, tris-(Beta -dimethylaminoethyl)amine, heptamethyltetraethylenepentamine,octamethylpentaethylenehexamine, and poly-(N-methylethyleneimine).
 5. Acomplex according to claim 1 wherein said chelating polyamine istris-2(dimethylaminoethyl)-amine.
 6. A complex according to claim 1wherein said sodium salt is sodium dimethyl amide and said tertiarychelating hydrocarbyl polyamine isN,N,N'',N'''',N''''-pentamethyl-diethylene-triamine.